mongo db.find无法正常工作

Question

I have the following script that I'm running through mongo shell. The first posts query executes fine and I receive the data object. Also if I print the date after the convertDate function, the correct date is returned. However in the second postdata findOne function I can't get any of the print statements to show anything. So there isn't an error but no results are found which should still show 'no record'. Am I missing something here?

db.posts.find().forEach(function(data) {

var date = convertDate(data.created_at);

  db.postdata.findOne({ company_id: data.company_id, date: date }, function(err, post){
    if (err) { print('err' + err) }
    if(post){
        print('test' + post);
    } else {
        print('no record');
    }
  });

});

Answer 1

findOne in the shell is synchronous so the found post is returned rather than passed into a callback.

db.posts.find().forEach(function(data) {
  var date = convertDate(data.created_at);
  var post = db.postdata.findOne({ company_id: data.company_id, date: date });
  if(post){
    print('test' + post);
  } else {
    print('no record');
  }
});